The earth is getting smaller

Our planet has shrunk. According to the latest measurements by Bonn scientists, the earth is a few millimeters smaller than previously assumed. This extremely precise determination of the diameter was made possible by radio waves that hit Earth from far away from space.

planet Earth

Bonn - As the researchers report in the "Journal of Geodesy", the new data can be used to better determine the rise in sea level as a result of climate change.

"We coordinated the worldwide measurements from 34 partners in 17 countries and brought the results together," says Axel Nothnagel from the Institute for Geodesy and Geoinformation at the University of Bonn. Radio telescopes have measured the radio waves from further quasars and their arrival time on earth. From the tiny time differences at the various measuring locations, the distance between the telescopes can be determined with an accuracy of two millimeters per 1000 kilometers. The researchers call this procedure "Very Long Baseline Interferometry".

The same measurements also showed that Europe and North America are drifting apart by 18 millimeters every year. The reason for this lies in the plate tectonics and in the area of ​​the mid-ocean ridge in the middle of the Atlantic, rising rock masses push the Atlantic plate and thus also the continents on it apart.

These measurements dwarf the accuracy of data from GPS position satellites. With the correction of the earth's diameter now possible, the height of the sea level and its rise due to global warming can also be determined more precisely.